Rebeca Muniz #Cedar

graphs/possible_bipartition.py

@@ -1,12 +1,56 @@
 # Can be used for BFS
 from collections import deque 
+class Graph():
 
-def possible_bipartition(dislikes):
+    def __init__(self, V):
+            self.V = V
+            self.graph = [[0 for column in range(V)] \
+                                    for row in range(V)]
+
+def possible_bipartition(self, dislikes):
     """ Will return True or False if the given graph
         can be bipartitioned without neighboring nodes put
         into the same partition.
-        Time Complexity: ?
-        Space Complexity: ?
+        Time Complexity: O(N+E)
+        Space Complexity: O(N)
     """
-    pass
-
+        colorArr = [-1] * self.V
+
+        # Assign first color to source
+        colorArr[dislikes] = 1
+
+        # Create a queue (FIFO) of vertex numbers and
+        # enqueue source vertex for BFS traversal
+        queue = []
+        queue.append(dislikes)
+
+        # Run while there are vertices in queue
+        # (Similar to BFS)
+        while queue:
+
+            u = queue.pop()
+
+            # Return false if there is a self-loop
+            if self.graph[u][u] == 1:
+                return False;
+
+            for v in range(self.V):
+
+                # An edge from u to v exists and destination
+                # v is not colored
+                if self.graph[u][v] == 1 and colorArr[v] == -1:
+
+                    # Assign alternate color to this
+                    # adjacent v of u
+                    colorArr[v] = 1 - colorArr[u]
+                    queue.append(v)
+
+                # An edge from u to v exists and destination
+                # v is colored with same color as u
+                elif self.graph[u][v] == 1 and colorArr[v] == colorArr[u]:
+                    return False
+
+        # If we reach here, then all adjacent
+        # vertices can be colored with alternate
+        # color
+        return True